Well, Daigasso Band Brothers is actually quite engrossing. (well, ok, just like in Donkey Konga, I could go without the royalty-free junk songs like "When The Saints are Marching in"..., but the good songs on the card definitely outnumber the not-so-great).
Each song in the game is divided into instruments. So you play it once for the guitar, once for the bass, once for the drum, etc. Each section's difficulty level is indicated by the number of stars (the higher the number, the more difficult it is).
Daigasso also has a very nifty score edit mode, whereas you can create your own song. When you start the game you have access to a basic editor (that captures sound via the mike), and there's a pro version unlockable in "studio recording" (ie. career) mode.